Leak proof needleless medical connector

ABSTRACT

A leak proof needleless medical connector has a housing, an actuator, a resilient member and an adapter. The housing includes a valve tube. The valve tube has a bottom annular blocking projection extending from an inner surface thereof. The actuator and the resilient member are mounted in the housing and the adapter is mounted on a top of the housing. A bottom valve stem is mounted in the valve tube of the housing. A gap is formed between the bottom valve stem and the valve tube. A bottom end of the bottom valve stem abuts the bottom annular blocking projection of the valve tube to close an open bottom of the valve tube. In use, a dosing unit is screwed into the needleless medical connector. Thus, a flow channel is formed within the needleless medical connector and the dosing unit to allow passage of medication.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to medical injectors, and moreparticularly to a needleless medical connector for preventing leakage ofmedication.

2. Description of the Related Art

A medical injector is used to inject medication into a patient. Aconventional medical injector comprises a syringe fitted with a needle.Medication is injected from the syringe into a patient through theneedle. However, the needle is unsafe and medical personnel mayaccidentally get stabbed by the needle. Accordingly, a needlelessmedical injector without using a needle has been developed.

When the needleless medical injector is in use, a needleless medicalconnector is screwed into the needleless medical injector and a dosingunit is then screwed into the needleless medical connector. Thus, a flowchannel is formed within the needleless medical connector and the dosingunit to allow passage of medication and injection of the medication intoa patient. After the necessary medication has been dispensed, the dosingunit is removed from the needleless medical connector. However, currentneedleless medical connectors have poor sealing property such thatleakage of the medication may occur when the dosing unit is removed.

To overcome the shortcomings, the present invention provides a leakproof needleless medical connector to mitigate or obviate theaforementioned problems.

SUMMARY OF THE INVENTION

The present invention provides a leak proof needleless medical connectorthat can prevent leakage of medication.

A leak proof needleless medical connector in accordance with the presentinvention comprises a housing, an actuator, a resilient member and anadapter. The housing includes a valve tube. The valve tube has a bottomannular blocking projection extending from an inner surface of the valvetube. The actuator is movably disposed within the housing. The resilientmember is disposed within the housing and includes in sequence a lowercompression tube, a column and an upper compression tube. The lowercompression tube and the upper compression tube are resilientlycompressible and expansible. The column has at least one through holedefined therethrough. An interior of the lower compression tubecommunicates with an interior of the upper compression tube through theat least one through hole of the column. A bottom valve stem is disposedin the lower compression tube. The lower compression tube is mountedaround the valve tube of the housing and the bottom valve stem ismounted in the valve tube. A gap is formed between the bottom valve stemand the valve tube. The gap does not communicate with the interior ofthe upper compression tube. A bottom end of the bottom valve stem abutsthe bottom annular blocking projection of the valve tube to close anopen bottom of the valve tube. A top valve stem is disposed in the uppercompression tube. The adapter is mounted on a top of the housing suchthat the resilient member is mounted between the adapter and theactuator. An interior of the adapter does not communicate with the atleast one through hole of the column because of the said top valve stem.In use, a dosing unit is screwed into the needleless medical connector.Thus, a flow channel is formed within the needleless medical connectorand the dosing unit to allow passage of medication.

Other objectives, advantages and novel features of the invention willbecome more apparent from the following detailed description when takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of the leak proofneedleless medical connector in accordance with the present invention;

FIG. 2 is an exploded perspective view of the leak proof needlelessmedical connector in FIG. 1;

FIG. 3 is an exploded cross-sectional perspective view of the leak proofneedleless medical connector in FIG. 1;

FIG. 4 is a cross-sectional side view of the leak proof needlelessmedical connector in FIG. 1;

FIG. 5 is a cross-sectional side view of the leak proof needlelessmedical connector in FIG. 1 shown in an actuated state;

FIG. 6 is an operational perspective view of the leak proof needlelessmedical connector in FIG. 1 showing that the needleless medicalconnector is engaged with a needleless medical injector;

FIG. 7 is an operational perspective view of the leak proof needlelessmedical connector in FIG. 1 with the needleless medical injector,showing that the needleless medical connector is engaged with one of thedosing units;

FIGS. 8 to 10 are operational cross-sectional side views of the leakproof needleless medical connector in FIG. 1 with the needleless medicalinjector and the dosing unit;

FIG. 11 is an exploded perspective view of a second embodiment of theleak proof needleless medical connector in accordance with the presentinvention;

FIG. 12 is an exploded cross-sectional perspective view of the leakproof needleless medical connector in FIG. 11;

FIG. 13 is a cross-sectional side view of the leak proof needlelessmedical connector in FIG. 11;

FIG. 14 is a cross-sectional side view of the leak proof needlelessmedical connector in FIG. 11 shown in an actuated state;

FIGS. 15 to 17 are operational cross-sectional side views of the leakproof needleless medical connector in FIG. 11 with a needleless medicalinjector and a dosing unit;

FIG. 18 is an exploded perspective view of a third embodiment of theleak proof needleless medical connector in accordance with the presentinvention;

FIG. 19 is an exploded cross-sectional perspective view of the leakproof needleless medical connector in FIG. 18;

FIG. 20 is a cross-sectional side view of the leak proof needlelessmedical connector in FIG. 18;

FIG. 21 is a cross-sectional side view of the leak proof needlelessmedical connector in FIG. 18 shown in an actuated state;

FIG. 22 is an exploded perspective view of a fourth embodiment of theleak proof needleless medical connector in accordance with the presentinvention;

FIG. 23 is an exploded cross-sectional perspective view of the leakproof needleless medical connector in FIG. 22;

FIG. 24 is a cross-sectional side view of the leak proof needlelessmedical connector in FIG. 22;

FIG. 25 is a cross-sectional side view of the leak proof needlelessmedical connector in FIG. 22 shown in an actuated state; and

FIGS. 26 to 29 are enlarged perspective views of spherical compressiontubes of the leak proof needleless medical connectors in accordance withthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1 to 4, a leak proof needleless medicalconnector in accordance with the present invention comprises a housing10, an actuator 20, a resilient member 30 and an adapter 40.

The housing 10 includes an outer casing 11, a valve tube 12 and anannular portion 13. A bottom portion of the outer casing 11 is providedwith internal threads 111. The valve tube 12 is disposed within theouter casing 11 and adjacent to the internal threads 111, and the valvetube 12 has an inner surface, an outer surface, a bottom annularblocking projection 121 and an abutting ring 122. The bottom annularblocking projection 121 extends from a bottom end of the inner surfaceof the valve tube 12. The abutting ring 122 extends from the outersurface of the valve tube 12. The annular portion 13 is formed betweenthe outer casing 11 and the valve tube 12 and has a plurality oflongitudinal guide holes 131 defined therethrough.

The actuator 20 is hollow, is movably disposed within the outer casing11 of the housing 10 and includes a collar 21 and a plurality of guidemembers 22. The collar 21 is mounted around the valve tube 12 of thehousing 10 above the annular portion 13 and has a top surface, a bottomsurface and a first annular receiving groove 211. The first annularreceiving groove 211 is formed in the top surface of the collar 21. Theguide members 22 extend downward from the bottom surface of the collar21. The guide members 22 correspond to and are inserted respectivelythrough the guide holes 131 of the annular portion 13 of the housing 10to allow the actuator 20 to move longitudinally only within the housing10. The abutting ring 122 of the valve tube 12 of the housing 10 abutsinner surfaces of the guide members 22.

The resilient member 30 is disposed within the outer casing 11 of thehousing 10 above the actuator 20 and includes in sequence a lowercompression tube 31, a column 32 and an upper compression tube 33. Thelower compression tube 31 and the upper compression tube 33 areresiliently compressible and expansible. The column 32 has at least onelongitudinal through hole 321 defined therethrough. An interior of thelower compression tube 31 communicates with an interior of the uppercompression tube 33 through the at least one through hole 321 of thecolumn 32. The lower compression tube 31 is mounted around the valvetube 12 of the housing 10 and a bottom end of the lower compression tube31 is received in the first annular receiving groove 211 of the collar21 of the actuator 20. A space 35 is formed between the valve tube 12and the lower compression tube 31. A top end of an inner surface of thelower compression tube 31 abuts a top end of the outer surface of thevalve tube 12 such that the space 35 does not communicate with the atleast one through hole 321 of the column 32. A bottom valve stem 34 isdisposed in the lower compression tube 31 and is mounted in the valvetube 12. A gap 36 is formed between the bottom valve stem 34 and thevalve tube 12. The gap 36 does not communicate with the interior of theupper compression tube 33. A bottom end of the bottom valve stem 34abuts the bottom annular blocking projection 121 of the valve tube 12 toclose an open bottom of the valve tube 12. A top valve stem 37 isdisposed in the upper compression tube 33.

The adapter 40 is hollow, is mounted on a top of the outer casing 11 ofthe housing 10 and includes a top annular member 41 and a bottom annularmember 42. The top annular member 41 is provided with external threads411. The bottom annular member 42 is inserted into the top of the outercasing 11 of the housing 10 such that a bottom end of the resilientmember 30 abuts the collar 21 of the actuator 20 and a top end of theresilient member 30 abuts the bottom annular member 42 of the adapter40. An interior of the adapter 40 does not communicate with the at leastone through hole 321 of the column 32 because of the said top valve stem37.

FIGS. 1 to 5 show a first embodiment of the leak proof needlelessmedical connector of the present invention.

The outer casing 11 of the housing 10 has an inner surface, an annularlocking projection 112 and a plurality of spaced longitudinal lockingribs 113. The annular locking projection 112 and the longitudinallocking ribs 113 extend from the inner surface of the outer casing 11.

The bottom valve stem 34 extends downward from a central portion of abottom surface of the column 32. The top valve stem 37 extends upwardfrom a central portion of a top surface of the column 32. The column 32has a plurality of through holes 321 defined therethrough. The throughholes 321 are spaced around the bottom valve stem 34 and the top valvestem 37. The bottom valve stem 34 has a flange 341 at its top end. Theflange 341 is inserted into a top of the gap 36 such that the gap 36does not communicate with the through holes 321 of the column 32. Thetop valve stem 37 has an enlarged portion 371 at its top end. Theenlarged portion 371 abuts a bottom end of an inner surface of thebottom annular member 42 of the adapter 40 such that the interior of theupper compression tube 33 does not communicate with the interior of theadapter 40. Walls of the lower and upper compression tubes 31, 33 may bewaved, or, with reference to FIG. 26, walls of the lower and uppercompression tubes 310, 330 may be spherical.

The bottom annular member 42 of the adapter 40 has a bottom surface, anouter surface, a second annular receiving groove 421, an annular lockinggroove 422 and a plurality of spaced longitudinal locking channels 423.The second annular receiving groove 421 is formed in the bottom surfaceof the bottom annular member 42. The top end of the upper compressiontube 33 is received in the second annular receiving groove 421. Theannular locking groove 422 and the longitudinal locking channels 423 areformed in the outer surface of the bottom annular member 42. The annularlocking projection 112 of the outer casing 11 of the housing 10corresponds to and engages the annular locking groove 422 to prevent theadapter 40 from being removed from the housing 10. The longitudinallocking ribs 113 of the outer casing 11 of the housing 10 correspond toand engage the longitudinal locking channels 423 to prevent the adapter40 from rotating relative to the housing 10.

In the first embodiment, the leak proof needleless medical connectorcomprises four components including the housing 10, the actuator 20, theresilient member 30 and the adapter 40. The lower compression tube 31,the column 32, the upper compression tube 33, the bottom valve stem 34and the top valve stem 37 are integrally formed to construct theresilient member 30.

With reference to FIG. 6, when the first embodiment of the leak proofneedleless medical connector is in use, the external threads 411 of thetop annular member 41 of the adapter 40 are screwed into internalthreads of a needleless medical injector 50. With reference to FIG. 7,external threads of an appropriate dosing unit 60, 60A, 60B are thenscrewed with the internal threads 111 of the outer casing 11 of thehousing 10. The following description describes a situation in which thedosing unit 60 is used. With reference to FIGS. 5 and 8, the dosing unit60 is screwed into the housing 10 to move the guide members 22 of theactuator 20 longitudinally within the housing 10, such that the actuator20 is moved up to compress the lower and upper compression tubes 31, 33.Under this circumstance, the bottom end of the bottom valve stem 34 ismoved away from the bottom annular blocking projection 121 of the valvetube 12 of the housing 10 to open the open bottom of the valve tube 12,the flange 341 of the bottom valve stem 34 is moved away from the top ofthe gap 36 to allow the gap 36 to communicate with the through holes 321of the column 32, and the enlarged portion 371 of the top valve stem 37does not abut the inner surface of the bottom annular member 42 of theadapter 40 to allow the interior of the upper compression tube 33 tocommunicate with the interior of the adapter 40.

When the dosing unit 60 is screwed into the housing 10, the valve tube12 of the housing 10 is inserted into the dosing unit 60 and compress aresilient member 61 of the dosing unit 60. Thus, the open bottom of thevalve tube 12 communicates with an interior of the dosing unit 60 and aflow channel is formed within the needleless medical connector and thedosing unit 60. With reference to FIG. 9, medication 70 in theneedleless medical injector 50 flows in sequence through the needlelessmedical connector, the dosing unit 60, and a fluid infusion tube 80connected to the dosing unit 60, and the medication 70 is then injectedinto a patient.

With reference to FIGS. 4 and 10, after the necessary medication hasbeen dispensed, the dosing unit 60 is removed from the needlelessmedical connector. The lower and upper compression tubes 31, 33 extendthemselves due to their resilience to produce three sealing effects asfollows. Firstly, the bottom end of the bottom valve stem 34 returns toabut the bottom annular blocking projection 121 of the valve tube 12 ofthe housing 10 and to close the open bottom of the valve tube 12.Secondly, the flange 341 of the bottom valve stem 34 returns to beinserted into the top of the gap 36. Thirdly, the enlarged portion 371of the top valve stem 37 returns to abut the inner surface of the bottomannular member 42 of the adapter 40. Therefore, the needleless medicalconnector has good sealing property to prevent leakage of themedication. In addition, the moment the dosing unit 60 is removed, avacuum is formed in the needleless medical connector and draws themedication remaining on the external surface of the needleless medicalconnector into the needleless medical connector such that no medicationresidue exists outside the needleless medical connector.

FIGS. 11 to 14 show a second embodiment of the leak proof needlelessmedical connector of the present invention.

The column 32A has a through hole 321A extending through a centralportion thereof. A top end of the bottom valve stem 34A is connected toa bottom end of an inner surface of the through hole 321A. A pluralityof spaced longitudinal depressions 322A are formed in the inner surfaceof the through hole 321A. Each depression 322A has an open bottomcommunicating with the interior of the lower compression tube 31A andthe gap 36A. Walls of the lower and upper compression tubes 31A, 33A maybe waved, or, with reference to FIG. 27, walls of the lower and uppercompression tubes 310A, 330A may be spherical.

The bottom annular member 42A of the adapter 40A has a bottom surfaceand a second annular receiving groove 421A. The second annular receivinggroove 421A is formed in the bottom surface of the bottom annular member42A. The top end of the upper compression tube 33A is received in thesecond annular receiving groove 421A. The top valve stem 43A extendsdownward from an interior of the bottom annular member 42A and has anouter surface and a plurality of spaced longitudinal channels 431A. Thechannels 431A are formed in the outer surface of the top valve stem 43A.Each channel 431A has an open top communicating with an interior of thetop annular member 41A of the adapter 40A. A bottom end of the top valvestem 43A abuts a top end of the inner surface of the through hole 321Aof the column 32A such that the interior of the upper compression tube33A does not communicate with the through hole 321A of the column 32A.

In the second embodiment, the leak proof needleless medical connectorcomprises four components including the housing 10A, the actuator 20A,the resilient member 30A and the adapter 40A. The lower compression tube31A, the column 32A, the upper compression tube 33A and the bottom valvestem 34A are integrally formed to construct the resilient member 30A.The top annular member 41A, the bottom annular member 42A and the topvalve stem 43A are integrally formed to construct the adapter 40A.

With reference to FIG. 7, when the second embodiment of the leak proofneedleless medical connector is in use, the needleless medical connectoris screwed into a needleless medical injector 50 and an appropriatedosing unit 60, 60A, 60B is then screwed into the needleless medicalconnector. The following description describes a situation in which thedosing unit 60 is used. With reference to FIGS. 14 and 15, the dosingunit 60 is screwed into the housing 10A to move the actuator 20A up andto compress the lower and upper compression tubes 31A, 33A. Under thiscircumstance, the bottom end of the bottom valve stem 34A is moved awayfrom the bottom annular blocking projection 121A of the valve tube 12Aof the housing 10A to open the open bottom of the valve tube 12A and toallow the open bottom of the valve tube 12A to communicate with aninterior of the dosing unit 60, and the bottom end of the top valve stem43A does not abut the inner surface of the through hole 321A of thecolumn 32A to allow the interior of the upper compression tube 33A tocommunicate with the through hole 321A of the column 32A through thechannels 431A of the top valve stem 43A. Thus, a flow channel is formedwithin the needleless medical connector and the dosing unit 60. Withreference to FIG. 16, medication 70 in the needleless medical injector50 flows in sequence through the needleless medical connector, thedosing unit 60, and a fluid infusion tube 80 connected to the dosingunit 60, and the medication is then injected into a patient.

With reference to FIGS. 13 and 17, after the necessary medication hasbeen dispensed, the dosing unit 60 is removed from the needlelessmedical connector. The lower and upper compression tubes 31A, 33A extendthemselves due to their resilience to produce three sealing effects asfollows. Firstly, the bottom end of the bottom valve stem 34A returns toclose the open bottom of the valve tube 12A of the housing 10A.Secondly, the top end of the inner surface of the lower compression tube31A returns to abut the outer surface of the valve tube 12A. Thirdly,the bottom end of the top valve stem 43A of the adapter 40A returns toabut the inner surface of the through hole 321A of the column 32A. Inaddition, the moment the dosing unit 60 is removed, a vacuum is formedin the needleless medical connector. Therefore, the needleless medicalconnector has good sealing property to prevent leakage of the medicationand no medication residue exists outside the needleless medicalconnector.

FIGS. 18 to 21 show a third embodiment of the leak proof needlelessmedical connector of the present invention.

The bottom valve stem 34B extends downward from a central portion of abottom surface of the column 32B. The column 32B has a plurality ofthrough holes 321B therethrough. The through holes 321B are spacedaround the bottom valve stem 34B. The bottom valve stem 34B has a flange341B at its top end. The flange 341B is inserted into a top of the gap36B such that the gap 36B does not communicate with the through holes321B of the column 32B. The top valve stem 37B is mounted upward from acentral portion of a top surface of the column 32B. The top valve stem37B has an enlarged portion 371B at its top end. Walls of the lower andupper compression tubes 31B, 33B may be waved, or, with reference toFIG. 28, walls of the lower and upper compression tubes 310B, 330B maybe spherical.

The bottom annular member 42B of the adapter 40B has a bottom surface,an inner surface, a second annular receiving groove 421B and a topannular blocking projection 424B. The second annular receiving groove421B is formed in the bottom surface of the bottom annular member 42B.The top end of the upper compression tube 33B is received in the secondannular receiving groove 421B. The top annular blocking projection 424Bextends from a bottom end of the inner surface of the bottom annularmember 42B. The enlarged portion 371B of the top valve stem 37B abutsthe top annular blocking projection 424B such that the interior of theupper compression tube 33B does not communicate with the interior of theadapter 40B.

In the third embodiment, the leak proof needleless medical connectorcomprises five components including the housing 10B, the actuator 20B,the resilient member 30B, the top valve stem 37B and the adapter 40B.The lower compression tube 31B, the column 32B, the upper compressiontube 33B and the bottom valve stem 34B are integrally formed toconstruct the resilient member 30B.

With reference to FIG. 7, when the third embodiment of the leak proofneedleless medical connector is in use, the needleless medical connectoris screwed into a needleless medical injector 50 and an appropriatedosing unit 60, 60A, 60B is then screwed into the needleless medicalconnector. The following description describes a situation in which thedosing unit 60 is used. With further reference to FIG. 21, the dosingunit 60 is screwed into the housing 10B to move the actuator 20B up andto compress the lower and upper compression tubes 31B, 33B. Under thiscircumstance, the bottom end of the bottom valve stem 34B is moved awayfrom the bottom annular blocking projection 121B of the valve tube 12Bof the housing 10B to open the open bottom of the valve tube 12B and toallow the open bottom of the valve tube 12B to communicate with aninterior of the dosing unit 60, the flange 341B of the bottom valve stem34B is moved away from the top of the gap 36B to allow the gap 36B tocommunicate with the through holes 321B of the column 32B, and theenlarged portion 371B of the top valve stem 37B is moved away from thetop annular blocking projection 424B of the bottom annular member 42B ofthe adapter 40B to allow the interior of the upper compression tube 33Bto communicate with the interior of the adapter 40B. Thus, a flowchannel is formed within the needleless medical connector and the dosingunit 60 to allow passage of medication and injection of the medicationinto a patient.

With reference to FIG. 20, after the necessary medication has beendispensed, the dosing unit 60 is removed from the needleless medicalconnector. The lower and upper compression tubes 31B, 33B extendthemselves due to their resilience to produce three sealing effects asfollows. Firstly, the bottom end of the bottom valve stem 34B returns toclose the open bottom of the valve tube 12B of the housing 10B.Secondly, the flange 341B of the bottom valve stem 34B returns to beinserted into the top of the gap 36B. Thirdly, the enlarged portion 371Bof the top valve stem 37B returns to abut the top annular blockingprojection 424B of the bottom annular member 42B of the adapter 40B. Inaddition, the moment the dosing unit 60 is removed, a vacuum is formedin the needleless medical connector. Therefore, the needleless medicalconnector has good sealing property to prevent leakage of the medicationand no medication residue exists outside the needleless medicalconnector.

FIGS. 22 to 25 show a fourth embodiment of the leak proof needlelessmedical connector of the present invention.

The lower compression tube 31C is mounted between the actuator 20C andthe column 32C and has a lower top plate 311C and a lower central hole312C. The lower central hole 312C extends through the lower top plate311C. The upper compression tube 33C is mounted between the column 32Cand the adapter 40C and has an upper top plate 331C and an upper centralhole 332C. The upper central hole 332C extends through the upper topplate 331C. The bottom valve stem 34C extends downward from a centralportion of a bottom surface of the column 32C. The top valve stem 37Cextends upward from a central portion of a top surface of the column32C. The column 32C has a plurality of through holes 321C therethrough.The through holes 321C are spaced around the bottom valve stem 34C andthe top valve stem 37C. A top of the valve tube 12C of the housing 10Cabuts a bottom surface of the lower top plate 311C of the lowercompression tube 31C to urge the lower top plate 311C toward the column32C to close open bottoms of the through holes 321C of the column 32Csuch that the through holes 321C do not communicate with the gap 36C.The top valve stem 37C has an enlarged portion 371C at its top end. Theenlarged portion 371C abuts an inner surface of the upper central hole332C of the upper compression tube 33C such that the interior of theupper compression tube 33C does not communicate with the interior of theadapter 40C. Walls of the lower and upper compression tubes 31C, 33C maybe waved, or, with reference to FIG. 29, walls of the lower and uppercompression tubes 310C, 330C may be spherical.

In the fourth embodiment, the leak proof needleless medical connectorcomprises six components including the housing 10C, the actuator 20C,the lower compression tube 31C, the column 32C, the upper compressiontube 33C and the adapter 40C. The bottom valve stem 34C and the topvalve stem 37C are integrally formed on the column 32C.

With reference to FIG. 7, when the fourth embodiment of the leak proofneedleless medical connector is in use, the needleless medical connectoris screwed into a needleless medical injector 50 and an appropriatedosing unit 60, 60A, 60B is then screwed into the needleless medicalconnector. The following description describes a situation in which thedosing unit 60 is used. With further reference to FIG. 25, the dosingunit 60 is screwed into the housing 10C to move the actuator 20C up andto compress the lower and upper compression tubes 31C, 33C. Under thiscircumstance, the bottom end of the bottom valve stem 34C is moved awayfrom the bottom annular blocking projection 121C of the valve tube 12Cof the housing 10C to open the open bottom of the valve tube 12C and toallow the open bottom of the valve tube 12C to communicate with aninterior of the dosing unit 60, the top of the valve tube 12C does notabut the lower top plate 311C of the lower compression tube 31C to allowthe gap 36C to communicate with the through holes 321C of the column 32Cthrough the lower central hole 312C of the lower compression tube 31C,and the enlarged portion 371C of the top valve stem 37C does not abutthe inner surface of the upper central hole 332C of the uppercompression tube 33C to allow the interior of the upper compression tube33C to communicate with the interior of the adapter 40C. Thus, a flowchannel is formed within the needleless medical connector and the dosingunit 60 to allow passage of medication and injection of the medicationinto a patient.

With reference to FIG. 24, after the necessary medication has beendispensed, the dosing unit 60 is removed from the needleless medicalconnector. The lower and upper compression tubes 31C, 33C extendthemselves due to their resilience to produce three sealing effects asfollows. Firstly, the bottom end of the bottom valve stem 34C returns toclose the open bottom of the valve tube 12C of the housing 10C.Secondly, the top of the valve tube 12C returns to abut the lower topplate 311C of the lower compression tube 31C. Thirdly, the enlargedportion 371C of the top valve stem 37C returns to abut the inner surfaceof the upper central hole 332C of the upper compression tube 33C. Inaddition, the moment the dosing unit 60 is removed, a vacuum is formedin the needleless medical connector. Therefore, the needleless medicalconnector has good sealing property to prevent leakage of the medicationand no medication residue exists outside the needleless medicalconnector.

Even though numerous characteristics and advantages of the presentinvention have been set forth in the foregoing description, togetherwith details of the structure and features of the invention, thedisclosure is illustrative only. Changes may be made in the details,especially in matters of shape, size and arrangement of parts within theprinciples of the invention to the full extent indicated by the broadgeneral meaning of the terms in which the appended claims are expressed.

What is claimed is:
 1. A leak proof needleless medical connectorcomprising: a housing including: an outer casing; and a valve tubedisposed within the outer casing and having: an inner surface; and abottom annular blocking projection extending from a bottom end of theinner surface of the valve tube; an actuator being hollow, movablydisposed within the outer casing of the housing and mounted around thevalve tube of the housing; a resilient member disposed within the outercasing of the housing and including in sequence: a lower compressiontube being resiliently compressible and expansible and mounted aroundthe valve tube of the housing; a column having at least one through holedefined therethrough; and an upper compression tube being resilientlycompressible and expansible, and an interior of the upper compressiontube communicating with an interior of the lower compression tubethrough the at least one through hole of the column; a bottom valve stemdisposed in the lower compression tube and mounted in the valve tube ofthe housing, a gap formed between the bottom valve stem and the valvetube and not communicating with the interior of the upper compressiontube, a bottom end of the bottom valve stem abutting the bottom annularblocking projection of the valve tube to close an open bottom of thevalve tube; a top valve stem disposed in the upper compression tube; andan adapter being hollow and mounted on a top of the outer casing of thehousing, the resilient member mounted between the adapter and theactuator, and an interior of the adapter not communicating with the atleast one through hole of the column because of the top valve stem. 2.The leak proof needleless medical connector as claimed in claim 1,wherein the housing includes an annular portion formed between the outercasing and the valve tube and having a plurality of guide holes definedthrough the annular portion; and the actuator includes a collar having abottom surface; and a plurality of guide members extending downward fromthe bottom surface of the collar and corresponding to and insertedrespectively through the guide holes of the annular portion of thehousing.
 3. The leak proof needleless medical connector as claimed inclaim 2, wherein the adapter includes a top annular member; and a bottomannular member inserted into the top of the outer casing of the housing.4. The leak proof needleless medical connector as claimed in claim 3,wherein the bottom valve stem extends downward from a bottom surface ofthe column, the top valve stem extends upward from a top surface of thecolumn, the column has a plurality of through holes definedtherethrough, the through holes are spaced around the bottom valve stemand the top valve stem, the bottom valve stem has a flange at its topend, the flange is inserted into a top of the gap such that the gap doesnot communicate with the through holes of the column, the top valve stemhas an enlarged portion at its top end, and the enlarged portion abutsan inner surface of the bottom annular member of the adapter such thatthe interior of the upper compression tube does not communicate with theinterior of the adapter.
 5. The leak proof needleless medical connectoras claimed in claim 4 comprising four components including the housing,the actuator, the resilient member and the adapter, wherein the lowercompression tube, the column, the upper compression tube, the bottomvalve stem and the top valve stem are integrally formed to construct theresilient member.
 6. The leak proof needleless medical connector asclaimed in claim 5, wherein the outer casing of the housing has an innersurface; and an annular locking projection and a plurality of spacedlongitudinal locking ribs extending from the inner surface of the outercasing; and the bottom annular member of the adapter has an outersurface; and an annular locking groove and a plurality of spacedlongitudinal locking channels formed in the outer surface of the bottomannular member, the annular locking projection of the outer casing ofthe housing corresponding to and engaging the annular locking groove,and the longitudinal locking ribs of the outer casing of the housingcorresponding to and engaging the longitudinal locking channels.
 7. Theleak proof needleless medical connector as claimed in claim 3, whereinthe column has a through hole defined therethrough, a top end of thebottom valve stem is connected to a bottom end of an inner surface ofthe through hole, a plurality of depressions are formed in the innersurface of the through hole, and each depression has an open bottomcommunicating with the interior of the lower compression tube and thegap; the top valve stem extends downward from an interior of the bottomannular member of the adapter and has an outer surface; and a pluralityof channels formed in the outer surface of the top valve stem, eachchannel having an open top communicating with an interior of the topannular member of the adapter, and a bottom end of the top valve stemabuts the inner surface of the through hole of the column such that theinterior of the upper compression tube does not communicate with thethrough hole of the column.
 8. The leak proof needleless medicalconnector as claimed in claim 7 comprising four components including thehousing, the actuator, the resilient member and the adapter, wherein thelower compression tube, the column, the upper compression tube and thebottom valve stem are integrally formed to construct the resilientmember, and wherein the top annular member, the bottom annular memberand the top valve stem are integrally formed to construct the adapter.9. The leak proof needleless medical connector as claimed in claim 3,wherein the bottom valve stem extends downward from a bottom surface ofthe column, the column has a plurality of through holes definedtherethrough, the through holes are spaced around the bottom valve stem,the bottom valve stem has a flange at its top end, the flange isinserted into a top of the gap such that the gap does not communicatewith the through holes of the column; the bottom annular member of theadapter has an inner surface; and a top annular blocking projectionextending from the inner surface of the bottom annular member, and thetop valve stem is mounted upward from a top surface of the column andhas an enlarged portion at its top end, and the enlarged portion abutsthe top annular blocking projection of the bottom annular member of theadapter such that the interior of the upper compression tube does notcommunicate with the interior of the adapter.
 10. The leak proofneedleless medical connector as claimed in claim 9 comprising fivecomponents including the housing, the actuator, the resilient member,the top valve stem and the adapter, wherein the lower compression tube,the column, the upper compression tube and the bottom valve stem areintegrally formed to construct the resilient member.
 11. The leak proofneedleless medical connector as claimed in claim 3, wherein the lowercompression tube has a lower top plate; and a lower central holeextending through the lower top plate; the upper compression tube has anupper top plate; and an upper central hole extending through the uppertop plate; and the bottom valve stem extends downward from a bottomsurface of the column, the top valve stem extends upward from a topsurface of the column, the column has a plurality of through holesdefined therethrough, the through holes are spaced around the bottomvalve stem and the top valve stem, a top of the valve tube of thehousing abuts a bottom surface of the lower top plate of the lowercompression tube to urge the lower top plate toward the column to closeopen bottoms of the through holes of the column such that the throughholes do not communicate with the gap, the top valve stem has anenlarged portion at its top end, and the enlarged portion abuts an innersurface of the upper central hole of the upper compression tube suchthat the interior of the upper compression tube does not communicatewith the interior of the adapter.
 12. The leak proof needleless medicalconnector as claimed in claim 11 comprising six components including thehousing, the actuator, the lower compression tube, the column, the uppercompression tube and the adapter, wherein the bottom valve stem and thetop valve stem are integrally formed on the column.
 13. The leak proofneedleless medical connector as claimed in claim 5, wherein walls of thelower and upper compression tubes are waved.
 14. The leak proofneedleless medical connector as claimed in claim 8, wherein walls of thelower and upper compression tubes are waved.
 15. The leak proofneedleless medical connector as claimed in claim 10, wherein walls ofthe lower and upper compression tubes are waved.
 16. The leak proofneedleless medical connector as claimed in claim 12, wherein walls ofthe lower and upper compression tubes are waved.
 17. The leak proofneedleless medical connector as claimed in claim 5, wherein walls of thelower and upper compression tubes are spherical.
 18. The leak proofneedleless medical connector as claimed in claim 8, wherein walls of thelower and upper compression tubes are spherical.
 19. The leak proofneedleless medical connector as claimed in claim 10, wherein walls ofthe lower and upper compression tubes are spherical.
 20. The leak proofneedleless medical connector as claimed in claim 12, wherein walls ofthe lower and upper compression tubes are spherical.